“East London is a hotspot … although there are offences across London.”

Mr Mackey’s comments come as four teenagers, two aged 17 and two 18, were arrested for possession of a suspected corrosive substance following a stop and search in Leytonstone, east London on Wednesday.

A bottle of suspected corrosive substance, gloves and a balaclava were recovered from the car the suspects were travelling in.

Last week, five separate male victims – all on mopeds and including a fast-food delivery driver – were allegedly targeted by two moped-riding attackers in north and east London.

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“We are seeing some links – although it has to be treated with caution because it’s a small data set – of a growing feature between named suspects in acid attacks who also feature in our gang matrix,” Mr Mackey said.

“So please don’t read that as gangs have all moved lock, stock and barrel into acid, but we are seeing a move across.

“We have hypotheses for this, we have tests that we think, ‘is it something around a focus on knives and knife crime sentencing’, but there is no evidence to support this yet. It’s just something that we are looking at.”